<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
<script>
    //接口地址：http://api.apiopen.top/getJoke
    const p =new Promise((resolve,reject)=>{

        
    //1.创建对象
    const xhr  =new XMLHttpRequest();
    //2.初始化
    xhr.open('GET','http://api.apiopen.top/getJoke');
    //3.发送
    xhr.send();
    //4.绑定事件，处理响应结果
    xhr.onreadystatechange = function(){
        //判断
        if (xhr.readyState ===4){
            //判断响应状态码 200-299
            if(xhr.status >=200 && xhr.status <300){
                resolve(xhr.response);

            }else{
                reject(xhr.status);
            }
        }
    }


    });

    p.then(function(value){
        console.log(value);

    },function(reason){
        console.log(reason);
    });

</script>
</body>
</html>